Semi-analytical modelling of buckling driven delamination in uniaxially compressed damaged plates

A geometrically nonlinear model is developed to investigate the buckling behaviour of plates with a pre-existing delamination under uniaxial compression. The Rayleigh-Ritz procedure, based on trigonometric out-of-plane displacement functions, is used in conjunction with potential energy principles to describe the buckling and postbuckling response. The formulation is enhanced with the introduction of a discrete cohesive zone model to allow the delamination to grow under further loading. Different cases are investigated with residual capacities of the plates being evaluated in the neighbourhood of a transitional depth of delamination, where the postbuckling behaviour changes from thin film to mixed mode to global buckling. The model is validated with the commercial finite-element code Abaqus and criteria are proposed such that the component may be exploited beyond the critical loads.